Latch for overhead doors

ABSTRACT

A LATCH FOR LOCKING AN OVERHEAD DOOR IN OPEN POSITION. THE LATCH HAS A LATCHING MEANS, DISCLOSED AS A HINGED FREE HANGING LATCH BAR, WHICH ENTERS INTO LATCHING ENGAGEMENT WITH THE UPPER EDGE OF THE DOOR WHEN THE LATTER SWINGS TO OPEN POSITION TO LOCK THE DOOR IN THIS POSITION, AND LATCH RELEASE MEANS CARRIED BY THE DOOR AND OPERABLE FROM THE LOWER EDGE OF THE DOOR FOR RETRACTING THE LATCHING MEANS FROM LATCHING ENGAGEMENT WITH THE OPEN DOOR.

1972 M. NUTTER 3,702,710

LATCHFOR OVERHEAD DOORS Filed Nov. 23, 1970 wwsuroe 26 L YLE M NUTTER v 42 Arrow/5y Umted States Patent 3,702,710 LATCH FOR OVERHEAD DOORS Lyle M. Nutter, 3252 Feather Ave, Baldwin Park, Calif. 91706 Filed Nov. 23, 1970, Ser. No. 91,688 Int. Cl. Ec 17/08 US. Cl. 292-235 7 Claims ABSTRACT OF THE DISCLOSURE A latch for locking an overhead door in open position. The latch has a latching means, disclosed as a hinged free hanging latch bar, which enters into latching engagement with the upper edge of the door when the latter swings to open position to lock the door in this position, and latch release means carried by the door and operable from the lower edge of the door for retracting the latching means from latching engagement with the open door.

BACKGROUND OF THE INVENTION Field of the invention This invention relates generally to overhead doors, such as overhead garage doors, and more particularly to a latch for locking such doors in open position.

Prior art Most residential garages are equipped with overhead doors which are hinged to swing between a vertical closed position within the door opening and a horizontal overhead open position. The door hinges have a compound linkage arrangement and include large coil springs which are connected between certain of the hinge links and the door frame to counterbalance the door. Without these springs, the doors, even in full open position, are subject to a large unbalance force tending to close the doors.

Overhead doors of this kind are hazardous under two conditions. These conditions are breakage of either or both door springs and weakening of the springs. Thus, if the springs break with the door open, the latter will descend with great force, and seriously injuring a person in its path. Weakening of the springs is hazardous for the reason that the weakened spring force, while perhaps sufiicient to retain the door in full open position, may not be capable of preventing the door from descending with substantial force if the door is moved slightly from full open position. Accordingly, there is the ever-present danger that a door with weak springs may suddenly drop and injure a person in its path.

Overhead door latches have been devised to overcome the above dangers by latching the door in open position. By way of example, an overhead door latch of this kind is disclosed in Pat. No. 2,807,460. These existing latches, however, suffer from certain disadvantages which this invention overcomes. Foremost among these disadvantages are complexity, high cost, difliculty of installation, lack of reliability, and others.

SUMMARY OF THE INVENTION The improved overhead door latch of this invention has a latching means, disclosed as a hinged free hanging latch Fee bar, which enters into latching engagement with the upper edge of the door when the latter swings to open position to lock the door in this position, and latch release means carried by the door and operable from the lower edge of the door for retracting the latching means from latching engagement with the open door. The latch bar of the disclosed door latch is attached to an overhead support of the garage or other structure containing the door in a manner such that when hanging free, the bar assumes a normal position under the action of gravity wherein a downwardly facing latch shoulder on the lower end of the bar is located to engage the upper door edge in open position to prevent closing movement of the door. When in its free hanging position, the front edge of the latch bar, that is, the edge facing the door, is located for engagemnet by the upper door edge as the door approaches open position in a manner such that the door cams the bar rearwardly to clear the door. Upon arrival of the door in full open position, the latch bar swings forwardly under the action of gravity into latching engagement with the door.

According to another feature of the invention, a latch release means is mounted on the door for releasing the latch means from the outwardly located lower edge of the door when in open position. In the disclosed embodiment, this latch release means is a lever which is rotatable against the latch bar to retract the latter from latching engagement with the door when latched in open position. The release lever is operated by a cable from the lower door edge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical section through a building structure such as a garage equipped with the present door latch and showing the door in closed position;

FIG. 2 is a section similar to FIG. 1 showing the door latched open;

FIG. 3 is a view taken on line 33 in FIG. 2;

FIG. 4 is an enlarged detail of the latch bar; and

FIG. 5 is an enlarged detail of the latch bar release.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate a building structure 10, in this instance a garage, having an overhead door 12 installed within an access opening 14 to the structure. The door is supported along its sides on the door frame 16 by means of compound hinges 18 for swinging of the door between its closed position of FIG. 1 and its open position of FIG. 2. The hinges 18 are conventional and thus need not be explained except to say that they embody coil springs 20 for counterbalancing the weight of the door.

The present invention provides a latching means 22 engageable with the upper edge 24 of the door 12 for latching the latter in open position and latch release means 26 for releasing the latching means from the upper edge 24. The illustrated latching means 22 is a free hanging latch bar having a hinge 30 at its upper end. At the lower end of the bar is a downwardly facing latch shoulder 32 and a stop shoulder 34 extending down from the rear edge of the latch shoulder in a plane parallel to the pivot axis of binge 30. These shoulders are formed by a notch in the bar and are lined by metal facing or wear plates 36.

Latch bar 22 is pivotally attached, by the hinge 30, to an overhead member 38 in the structure 10 with the pivot axis of the bar parallel to the door edges 24, 28. The hinge is located so that the bar tends to assume a free hanging position under the force of gravity wherein the latch shoulder 32 is located to engage over the upper door edge 24 when the door 12 is in open position. The stop shoulder 34 then abuts the upper door edge to limit forward swinging of the bar. In the particular embodiment shown, the latch bar 22 is hinged so that its upper end is located forwardly of the upper edge of the door, when in open position, and the bar inclines rearwardly, i.e., away from the door opening 14, relative to its free hanging position when in latching engagement with the door. As a consequence, during opening movement of the door, its upper edge 24 engages the bar and earns the latter rearwardly from its free hanging position of FIG. 1 to clear the door. Upon arrival of the door in full open position, the bar swings forwardly into latching engagement with the door wherein the stop shoulder 34- abuts and the latch shoulder 32 engages over the upper door edge. As shown best in FIG. 2, these shoulders are inclined at oblique angles relative to the longitudinal axis of the latch bar to seat fiat against the door.

Latch release means 26 comprises a latch release member 40 which is mounted on the inner side of the door .12, i.e., the underside of the door when in open position, adjacent the upper door edge 24. This release member is movable between a retracted position (FIG. wherein the member is located to clear the latch bar 22 for latching engagement of the latter with the door in open position and an extended position wherein the member is located to engage the bar and retain the latter in rear retracted position out of latching engagement with the door. Connected to the release member is a spring 42 for urging the member to retracted position. An operating means 43 is connected to the member for extending the member against spring action from the lower door edge 28. The illustrated latch release member 40 is a lever pivoted between its ends at 44 on the underside of the door 12. One end of this lever is located to engage a bracket plate 46 on the latch bar 22 and swing the latter rearwardly from latching engagement with the door upon counterclockwise rotation of the lever in FIG. 5 to extended position with the door open. Spring 42 is connected between this lever end and the door to urge the lever in the clockwise direction to a retracted position against a stop 48 on the door.

The latch release operating means 4'3 is a'cable, one end of which is attached to the end of lever 40 opposite the spring 42. Cable 43 passes around a pulley 50 and through a guide 52 on the door and has a handle 54 attached to its end. Handle 54 is located adjacent the lower door edge 28. It will now be understood that pulling on the handle 54 rotates the lever 40 to extended position.

From the preceding description it is evident that when the door 12 is closed, the latch bar 22 hangs free in its vertical position of FIG. 1 and the latch release lever 40 is retracted by its spring 42. During moveemnt of the door to open position, the upper door edge 24 engages the bar and cams the latter rearwardly to clear the door. The bar then swings forwardly by gravity into latching engagement with the door upon arrival of the latter in open position. The latch bar is retracted from latching engagement with the door to release the latter 'for closing by pulling on the latch release handle 54.

What is claimed as new in support of Letters Patent is:

1. In combination with a structure having an opening, and an overhead door swingably mounted in said opening for movement between a vertical closed position within said opening and a horizontal overhead open position wherein the normally upper edge of the door is located within said structure and the normally lower edge of the door is located beyond said opening, a door latch for locking said door in open position comprising:

4 a latch bar having normally upper and lower ends and a downwardly presented latch shoulder at said lower end, and hinge means pivotally securing the upper end of said bar to said structure at a position within said structure which is located above the level of said door when said door is in open position in a manner such that said bar when hanging free assumes a normal position under the force of gravity wherein said latch shoulder is disposed to engage said door in open position adjacent its upper edge to lock the door against swinging to closed position, and the door engages the bar to cam the latter clear of the door during swinging of the latter to open position.

2. A door latch according to claim 1 including:

means operable from a position adjacent said lower door edge when said door is latched in open position for swinging said bar out of latching engagement with said door and normally releasing said bar for free swinging movement into latching engagement with said door.

3. A door latch according to claim 2 wherein:

said releasing means is mounted on said door adjacent the lower edge of said door.

4. A door latch according to claim 3 wherein:

said releasing means comprises a latch release member mounted on said door adjacent its upper edge for movement between a retracted position wherein said member is located to clear said bar for swinging to its latching position when the door is in open position and an extended position wherein said member is located to engage said bar and hold the latter out of latching position when said door is in open position, whereby extension of said member with said door latched in open position swings said bar out of latching engagement with said door, a spring for urging said member to retracted position, and operating means connected to said member and operable from the lower edge of said door for extending said member against spring action.

5. A door latch according to claim 4 wherein:

said latch release member is a pivoted lever, and said operating means is a cable.

6. In combination with a structure having an opening, and an overhead door swingably mounted in said opening for movement between a vertical closed position within said opening and a horizontal overhead open position wherein the normally upper edge of the door is located within said structure and the normally lower edge of the door is located beyond said opening, a door latch for locking said door in open position comprising:

latching means mounted on said structure for movement into and from latching engagement with the upper edge of said door when in open position to lock said door in open position and arranged to normally engage and latch said door upon movement of said door to open position; and

latch release means on said door operable from the lower edge of said door for engaging and releasing said latching means when said door is in open position.

'7. A door latch according to claim 6 wherein:

said latch release means comprises a latch release member mounted on said door adjacent its upper edge for movement between a retracted position wherein said member is located to clear said latching means for latching said door upon movement of the latter to open position and an extended position wherein said member is located to engage and retain said latching means out of latching engagement with said door when in open position, whereby extension of said member with said door latched in open position releases said latching means to permit closing of said door, a spring for urging said member to retracted position, and means operab 1e from the lower ec ige FOREIGN PATENTS 2:521: door for extendmg sa1d member agamst sprlng 129,746 10/1918 Great Briflain References Cited OTHER REFERENCES UNITED STATES PA NT 5 Popular Mechanics: May 1948, p. 173, Self-Setting 2,660,765 12/1953 Carlson 292-Dig. 36 Gamgww Prop? $321222 $1132? 533 3 5533 RICHARD MOORE, i y Examiner 1,3325%; Z133? 83362;;:iiiiiiiii'ziii 10 2,307,460 9/1957 Guimont 49-30 2 4, 262 

